P resident Donald Trump said on Friday he's ordered two nuclear submarines to move in the "appropriate regions" in response to what he called "highly provocative statements" from the deputy chair of Russia's security council, Dmitry Medvedev.

Tension between the U.S. and Russia has escalated this week as Trump and Medvedev have exchanged harsh statements toward each other.

Dmitry Medvedev recently taunted President Donald Trump for shifting positions on the Russia-Ukraine war, likening it to a seesaw.